diff --git a/doc/evolution.md b/doc/evolution.md
index c65ce8f..aae221e 100644
--- a/doc/evolution.md
+++ b/doc/evolution.md
@@ -1405,6 +1405,7 @@ Everything that was built and then killed, in roughly chronological order.
 | Named sandbox profiles (default, restricted, remote) | One config: `sandbox.yaml`. Multi-profile system was unused complexity |
 | `TurnCtx` struct | Eliminated; loop functions became methods on `*Agent` |
 | Bypass via custom Unix socket protocol | Replaced by bypass via 9P namespace |
+| `.meta` as sidecar to an executable | `.meta` IS the tool definition; executable is optional (tool-definitions.md) |
 | `subagent_generate` (JIT agent config tool) | Obsolete; sub-agents use existing profiles directly |
 | Fire-and-forget `subagent_spawn` via D-Bus | Replaced by blocking `ollie-9p rdwr agent/new` — returns the reply |
 | Sub-agents as peer agents (no parent, no return) | Replaced by task-scoped sub-agents with context inheritance and automatic cleanup |